This invention relates to a composite expandable device with a polymeric covering on the device and a bioactive coating on device and the polymeric covering, a delivery apparatus and a method.
Saphenous vein grafts have heretofore been utilized for bypassing occluded arterial blood vessels in the heart. Because they are vein tissue rather than arterial tissue, they have different characteristics and generally do not function well long term as arterial vessels. Saphenous bypass veins are less muscular and are generally quite flimsy and compliant. When these saphenous vein grafts become diseased with age, stenoses and obstructive deposits which are cheesy or buttery in consistency and which are very malleable are formed which cannot be treated effectively with interventional catheter procedures even when followed with a stent implant. The plaque material forming the stenosis tends to ooze through the stent struts and reoccludes flow passage through the stent and the saphenous vein graft. Other vascular obstructions, such as in femoral and popliteal vessels and in carotids as well as in native coronary arteries also suffer from occlusions. In many of these cases, plaque proliferates through the stents when stents are deployed in the vessels. Therefore a great need exits for a new and improved device and method to provide a lasting therapeutic relief in such situations.
In general, it is an object of the present invention to provide a composite expandable device with a substantially impervious polymeric covering thereon with a bioactive coating on the device and covering and a method for using the same which can be utilized for treating occlusions or partial occlusions in blood vessels and particularly saphenous vein grafts.
Another object of the invention is to provide a device of the above character which will provide a lasting therapeutic solution to the occurrence of plaque in stents in saphenous vein grafts.
Another object of the invention is to provide a device of the above character which can be used for repaving with endothelial cells the portion of the vessel being treated.
Another object of the invention is to provide a device of the above character which has physical characteristics which substantially match or mimic the physical characteristics of blood vessels.
Another object of the invention is to provide a device of the above character in which a uniformly distributed structural support is provided for the polymeric covering.
Another object of the invention is to provide a device of the above character which is very flexible and can bend axially to accommodate the tortuosity of blood vessels.
Another object of the invention is to provide a device of the above character which can be placed in tandem with another similar device in a vessel to treat a long stenosis in a vessel.
Additional objects and features of the invention will appear from the following description in which the preferred embodiments are set forth in detail in conjunction with the accompanying drawings.